One beautification technique of the ancient Norsemen was to file their teeth, a new study shows. A Swedish anthropologist analyzed 557 Viking skeletons dating from A.D. 800 to 1050 and discovered that 24 of them bore deep, horizontal grooves across their upper front teeth.

It's the first time that dental modification—a practice found in cultures around the world—has been seen in human skeletons from Europe.

"[These] unique finds of deliberate dental modification … reveal what we did not know before, that this custom is practiced around the world and also in Europe," said Caroline Alcini, an anthropologist at the National Heritage Board in Lund, Sweden.

Alcini led the study, which was published in the American Journal of Physical Anthropology.

The Vikings lived in Scandinavia from around A.D. 750 to 1100. They are best known for their sea voyages and violent raids of churches and monasteries in Britain and France.

The Norsemen also traveled to North America around A.D. 1000, some 500 years before Christopher Columbus set foot in the New World.

In the 1960s archaeologists discovered and excavated the remains of a thousand-year-old Norse encampment at the northern tip of Newfoundland, Canada.

Researchers say the Vikings may have learned the practice of filing their teeth from a foreign culture.

"Vikings are well known for their acquisitive habits, but until now we've thought of this in terms of gold, silver, and booty, not facial decoration," said William Fitzhugh, a Viking expert at the Smithsonian National Museum of Natural History in Washington, D.C.